2 ;^ • : ,\ .'Preparation, of Substances 



200 grams of the material used. Record the 

 amount. 



(6) From the equation given above cal- 

 culate the number of grams (b) of H2SO4 

 necessary to react with (a) grams of Ca3P208. 

 Note the number. 



(c) Read the specific gravity of the 

 chamber acid from the spindle floating in the 

 acid on the side shelf, Refer to the table of 

 specific gravity and read off the weight of 

 the H2SO4 in 1 cc. of the chamber acid. 

 Calculate the number of cubic centimeters 

 of chamber acid (c) necessary to contain 

 the (6) grams of H2SO4. Record the 

 volum. 



(d) The chamber acid is too strong to be 

 used directly on the rock phosphate and must 

 be diluted until it has the specific gravity 

 1.53. Calculate the number of cubic centi- 

 meters {d) of this acid necessary to contain 

 (b) grams of sulfuric acid. This is the volum 

 to which (c) cubic centimeters of chamber 

 acid should be diluted before the rock phos- 

 phate is added to it. Record the number. 



Tabulate the results of the four calcula- 

 tions as indicated below and have them veri- 

 fied by an instructor before proceding with 

 the work. 



